This invention relates to an improved catalyst for reforming of methanol to hydrogen and carbon monoxide and a process of preparing the same.
In conventional catalysts for reforming of methanol to hydrogen and carbon monoxide, active alumina or a silica base inorganic oxide is usually used as the material of the catalyst support or carrier. As the catalytic substance to be deposited on the carrier, it is usual to employ a metal or metals of the platinum group such as platinum, palladium, rhodium and/or ruthenium, or a base metal or base metals, such as chronium, manganese, iron, cobalt, nickel, copper and/or zinc or oxide(s) thereof. In such conventional catalysts, generally the noble metals have been accepted as superior to the base metals in terms of both conversion efficiency or catalytic activity on the decomposition of methanol to hydrogen and carbon monoxide and durability of the catalyst exposed to vaporized methanol in heated state, and platinum, rhodium and palladium have been taken as particularly advantageous.
From a practical point of view, however, the conventional catalysts are still unsatisfactory in their activity, durability and selectivity for the intended decomposition reaction of methanol to hydrogen and carbon monoxide even when metals of the platinum group are used as the catalytic material. Therefore, there is a trend of depositing a considerably large amount of noble metal on the carrier in producing conventional catalysts of the above described type with a view to improving the activity and durability of the catalysts, particularly the activity at relatively low temperatures and durability under practical reforming conditions including the adaptability to the reforming processes in which vaporized methanol is passed through a catalyst column or bed at a relatively high space velocity. However, such compensative measures are of limited effect and inevitably lead to a considerable rise in the cost of the catalysts, which offers a serious problem to the reforming of methanol on the commercial basis.